1. Field of the Invention
The present invention relates to a print control apparatus, a printing system, and a print control method.
2. Description of the Related Art
There has been a known printing method, in which a color image as a target image of color printing is formed with color toners of C (cyan), M (magenta), Y (yellow), and K (black) and a corporate logo etc. is superimposed on the target color image such that the logo etc. does not influence the target color image nor stand out. To prevent the superimposed logo etc. from standing out, printing is performed by using a clear toner that is colorless and transparent and adding gloss so that the visibility can be obtained without colors. The superimposed image as mentioned above is called a watermark.
Meanwhile, a primary target image to be printed is generally a black or color image, but in some cases, printing is performed so as to set a gloss effect or a matt effect to a part of the target image. To set the surface effect as mentioned above, the clear toner is used. If the amount of toner attached to a region of an image is uniform, the surface of the region becomes glossy. If the amount of toner in the region is not uniform with only the CMYK toners, gloss can be set to the surface by adding a certain amount of the clear toner needed to make the amount of toner in the region uniform.
There has been a known technology for obtaining gloss by using the clear toner in a region that is not glossy because toner is non-uniformly attached to the region. For example, Japanese Patent No. 3066995 discloses a technology for realizing a gloss tone by forming an image with a constant amount of transparent toner (clear toner) in a region where the gloss is desired.
On the other hand, it is possible to realize the matt effect by adding the clear toner to color toners, such as the CMYK toners, so as to purposely generate irregularity to vary the amount of the attached toner over the region.
In general, the corporate logo etc. as mentioned above is independent of the primary target color image, is provided as a simple cell pattern repeatedly placed on the entire surface, and is arranged independently of the primary target color image of the printed matter. Therefore, the primary color image and the corporate logo often overlap each other at some portions, where a conflict occurs between the above-mentioned two types of methods of using the clear toner.
However, when the matt effect is desired in any region of a color image and if a part of the corporate logo overlaps the region, it is necessary to determine whether to give priority to the effect on the color image with sacrifice of the corporate logo or to give priority to the corporate logo with sacrifice of the effect on the color image. Specifically, there is a demand to perform exclusion control related to a clear-toner application method in an overlapping area of a region where a glossy and transparent image is provided and a region where a gloss or matt is applied to the color image.
Therefore, there is a need for a print control apparatus, a printing system, and a print control method capable of efficiently perform exclusion control related to the clear-toner application method in an overlapping area of a region where a glossy and transparent image appears and a region where the surface effect is applied to the color image.